/* * OF helpers for parsing display timings * * Copyright (c) 2012 Steffen Trumtrar <s.trumtrar@pengutronix.de>, Pengutronix * * based on of_videomode.c by Sascha Hauer <s.hauer@pengutronix.de> * * This file is released under the GPLv2 */ #include <linux/export.h> #include <linux/of.h> #include <linux/slab.h> #include <video/display_timing.h> #include <video/of_display_timing.h> /** * parse_timing_property - parse timing_entry from device_node * @np: device_node with the property * @name: name of the property * @result: will be set to the return value * * DESCRIPTION: * Every display_timing can be specified with either just the typical value or * a range consisting of min/typ/max. This function helps handling this **/ static int parse_timing_property(const struct device_node *np, const char *name, struct timing_entry *result) { struct property *prop; int length, cells, ret; prop = of_find_property(np, name, &length); if (!prop) { pr_err("%s: could not find property %s\n", of_node_full_name(np), name); return -EINVAL; } cells = length / sizeof(u32); if (cells == 1) { ret = of_property_read_u32(np, name, &result->typ); result->min = result->typ; result->max = result->typ; } else if (cells == 3) { ret = of_property_read_u32_array(np, name, &result->min, cells); } else { pr_err("%s: illegal timing specification in %s\n", of_node_full_name(np), name); return -EINVAL; } return ret; } /** * of_parse_display_timing - parse display_timing entry from device_node * @np: device_node with the properties **/ static int of_parse_display_timing(const struct device_node *np, struct display_timing *dt) { u32 val = 0; int ret = 0; memset(dt, 0, sizeof(*dt)); ret |= parse_timing_property(np, "hback-porch", &dt->hback_porch); ret |= parse_timing_property(np, "hfront-porch", &dt->hfront_porch); ret |= parse_timing_property(np, "hactive", &dt->hactive); ret |= parse_timing_property(np, "hsync-len", &dt->hsync_len); ret |= parse_timing_property(np, "vback-porch", &dt->vback_porch); ret |= parse_timing_property(np, "vfront-porch", &dt->vfront_porch); ret |= parse_timing_property(np, "vactive", &dt->vactive); ret |= parse_timing_property(np, "vsync-len", &dt->vsync_len); ret |= parse_timing_property(np, "clock-frequency", &dt->pixelclock); dt->flags = 0; if (!of_property_read_u32(np, "vsync-active", &val)) dt->flags |= val ? DISPLAY_FLAGS_VSYNC_HIGH : DISPLAY_FLAGS_VSYNC_LOW; if (!of_property_read_u32(np, "hsync-active", &val)) dt->flags |= val ? DISPLAY_FLAGS_HSYNC_HIGH : DISPLAY_FLAGS_HSYNC_LOW; if (!of_property_read_u32(np, "de-active", &val)) dt->flags |= val ? DISPLAY_FLAGS_DE_HIGH : DISPLAY_FLAGS_DE_LOW; if (!of_property_read_u32(np, "pixelclk-active", &val)) dt->flags |= val ? DISPLAY_FLAGS_PIXDATA_POSEDGE : DISPLAY_FLAGS_PIXDATA_NEGEDGE; if (of_property_read_bool(np, "interlaced")) dt->flags |= DISPLAY_FLAGS_INTERLACED; if (of_property_read_bool(np, "doublescan")) dt->flags |= DISPLAY_FLAGS_DOUBLESCAN; if (of_property_read_bool(np, "doubleclk")) dt->flags |= DISPLAY_FLAGS_DOUBLECLK; if (ret) { pr_err("%s: error reading timing properties\n", of_node_full_name(np)); return -EINVAL; } return 0; } /** * of_get_display_timing - parse a display_timing entry * @np: device_node with the timing subnode * @name: name of the timing node * @dt: display_timing struct to fill **/ int of_get_display_timing(struct device_node *np, const char *name, struct display_timing *dt) { struct device_node *timing_np; if (!np) return -EINVAL; timing_np = of_get_child_by_name(np, name); if (!timing_np) { pr_err("%s: could not find node '%s'\n", of_node_full_name(np), name); return -ENOENT; } return of_parse_display_timing(timing_np, dt); } EXPORT_SYMBOL_GPL(of_get_display_timing); /** * of_get_display_timings - parse all display_timing entries from a device_node * @np: device_node with the subnodes **/ struct display_timings *of_get_display_timings(struct device_node *np) { struct device_node *timings_np; struct device_node *entry; struct device_node *native_mode; struct display_timings *disp; if (!np) return NULL; timings_np = of_get_child_by_name(np, "display-timings"); if (!timings_np) { pr_err("%s: could not find display-timings node\n", of_node_full_name(np)); return NULL; } disp = kzalloc(sizeof(*disp), GFP_KERNEL); if (!disp) { pr_err("%s: could not allocate struct disp'\n", of_node_full_name(np)); goto dispfail; } entry = of_parse_phandle(timings_np, "native-mode", 0); /* assume first child as native mode if none provided */ if (!entry) entry = of_get_next_child(timings_np, NULL); /* if there is no child, it is useless to go on */ if (!entry) { pr_err("%s: no timing specifications given\n", of_node_full_name(np)); goto entryfail; } pr_debug("%s: using %s as default timing\n", of_node_full_name(np), entry->name); native_mode = entry; disp->num_timings = of_get_child_count(timings_np); if (disp->num_timings == 0) { /* should never happen, as entry was already found above */ pr_err("%s: no timings specified\n", of_node_full_name(np)); goto entryfail; } disp->timings = kzalloc(sizeof(struct display_timing *) * disp->num_timings, GFP_KERNEL); if (!disp->timings) { pr_err("%s: could not allocate timings array\n", of_node_full_name(np)); goto entryfail; } disp->num_timings = 0; disp->native_mode = 0; for_each_child_of_node(timings_np, entry) { struct display_timing *dt; int r; dt = kzalloc(sizeof(*dt), GFP_KERNEL); if (!dt) { pr_err("%s: could not allocate display_timing struct\n", of_node_full_name(np)); goto timingfail; } r = of_parse_display_timing(entry, dt); if (r) { /* * to not encourage wrong devicetrees, fail in case of * an error */ pr_err("%s: error in timing %d\n", of_node_full_name(np), disp->num_timings + 1); goto timingfail; } if (native_mode == entry) disp->native_mode = disp->num_timings; disp->timings[disp->num_timings] = dt; disp->num_timings++; } of_node_put(timings_np); /* * native_mode points to the device_node returned by of_parse_phandle * therefore call of_node_put on it */ of_node_put(native_mode); pr_debug("%s: got %d timings. Using timing #%d as default\n", of_node_full_name(np), disp->num_timings, disp->native_mode + 1); return disp; timingfail: if (native_mode) of_node_put(native_mode); display_timings_release(disp); disp = NULL; entryfail: kfree(disp); dispfail: of_node_put(timings_np); return NULL; } EXPORT_SYMBOL_GPL(of_get_display_timings); /** * of_display_timings_exist - check if a display-timings node is provided * @np: device_node with the timing **/ int of_display_timings_exist(struct device_node *np) { struct device_node *timings_np; if (!np) return -EINVAL; timings_np = of_parse_phandle(np, "display-timings", 0); if (!timings_np) return -EINVAL; of_node_put(timings_np); return 1; } EXPORT_SYMBOL_GPL(of_display_timings_exist);